[MobWalk]

http://en.wikipedia.org/wiki/Pleasure_center#Experiments_on_...

Using the expression "what you fundamentally value" is not the right way to put it. In real life, what you fundamentally value changes on a minute-by-minute basis. If you were able to ask a rat what he valued, he would probably say food and water, aka survival. However, as soon as they put this rat into a Skinner box, it literally pleases itself until it dies of exhaustion, even though food and water were available to it.

I agree with you that the best way to run an AI/VI like this would be to skip the idea of "pleasure" entirely and simply make productivity its' fundamental value. You would also set it up so that while it could modify its' own source code, it could not change what it valued. It seems like it would be relatively easy to set it up so that it would "hide" parts of its' code from itself and make it off-limits from modification.